Bulb Removal Research Articles

Effect of management practice and bulb sizes for quality bulb production in Lilium (Lilium sp.)

An experiment was conducted at Floriculture division of Horticulture Research Centre, BARI, Gazipur, during November 2019 - June 2021 to study the effect of management practices and bulb sizes on production of quality bulb and bulblets of lilium (Lilium sp.). Two management practices, viz. removal of spikes and without removal of spikes were considered as one factor and three bulb sizes, viz. large, medium and small as another factor in a randomized complete block design. Removal of spikes produced maximum number of bulbs and bulblets/plant (1.41 and 1.81, respectively), the heaviest and largest bulb (26.02g and 4.47cm) and bulblets/plant (6.88g). Large-sized bulbs produced maximum number of bulbs and bulblets/plant (1.51 and 1.98, respectively), heaviest and largest bulb (27.80g and 4.67cm, respectively) and bulblets/plant (7.92g). The removal of spikes produced longest plant (52.58 cm), spike (64.05 cm), rachis (22.18 cm) and bud (8.69 cm) and largest bud and floret (2.80 and 16.96 cm, respectively) and maximum number of florets/stick (4.78) from bulbs obtained during first year. Considering various levels of bulb sizes, large-sized bulbs produced longest plant (53.77 cm), spike (67.22 cm), rachis (23.17 cm) and bud (8.86 cm) and largest bud and florets (2.86 and 17.14 cm, respectively) and maximum number of florets/stick (5.11) from bulbs obtained during the first year. Similarly, removal of spikes and large-sized bulbs produced a good number of bulbs and bulblets during second year from bulbs obtained during the first year. Large-sized bulbs combined with removal of spikes produced quality bulbs as well as flowers.

Vaginal light bulb removal with ligature loop device

Vaginal light bulb removal with ligature loop device

Artocarpus heterophyllus Lam (jackfruit) processing equipment: Research insights and perspectives

AbstractIndia is the largest producer of jackfruit (Artocarpus Heterophyllus Lam.) all over the world. It is an underutilized seasonal fruit rich in vitamins, minerals, proteins, and carbohydrates. A significant chunk of the jackfruit production is wasted due to a lack of postharvest technological interventions. Due to its bulky nature, thickness, and spiky skin, operations like peeling, cutting, and coring are difficult to perform manually. Recently, there is a considerable improvement in the mechanization of jackfruit postharvest processing, which helps to reduce the wastage by 80% in its production and utilization. This review summarizes the recently developed varied types of machinery, procedures, and working mechanism of various postharvest operations such as peeling, cutting, coring, bulb removal, and seed processing. Moreover, it critically evaluates and compares the machinery for each stage of unit operation involved in jackfruit processing. The development of various thermal processing techniques such as blanching, canning, boiling, and drying is also discussed in detail. However, on comparing thermal processing with other processing aids, there is always a critical nutrients loss during thermal processing. This review also finally explores the jackfruit potential for industrial application and commercialization.Practical ApplicationsUnit operations involving preprocessing of jackfruits such as peeling, cutting, coring, bulb removal, seed roasting, and seed dehulling remain the most tedious operation in jackfruit processing due to its irregular shape and hard surface. Manual operation of such unit operations consumes much time and causes drudgery. Hence, the development of suitable equipment for such unit operations becomes inevitable and helps make the jackfruit processing faster and more efficient. Critical analysis of various machineries for jackfruit processing will be of great use for industries to learn about various machineries used in jackfruit processing.

The effects of olfactory bulb removal on single-pellet skilled reaching task in rats.

We focused on how the rat uses olfactory cues in a single-pellet reaching task, which is composed of three successive learned responses, Orient, Transport, and Withdrawal. Orient comprised: front wall detection, slot localisation, and nose poke until reach start. High-speed video-recording enabled us to describe the temporal features of this sequence in controls vs. 3-5 and 12-14days after bilateral bulbectomy in trials with (P trial) vs. without (no-P trial) pellet. In controls, the full sequence was complete in P trials, while it was interrupted after Orient in no P-trials. After bulbectomy, the full sequence was seen in both P and no-P trials at days 3-5 and 12-14 and there was an increase in Orient duration due to the increased time in slot/shelf localisation. Unlike in controls, in anosmic rats, the first nose contact with the front wall took place below the slot/shelf level, and the number of nose touches together with the number of whisker cycles was significantly higher at 3-5 but not at 12-14days. The relationship between nose touches and whisker cycles was linear in all experimental conditions. Bulbectomy resulted in no changes in the Transport duration or the time the paw spent out of the slot. These findings suggest that olfaction allows the animal to orient itself in pellet localisation, and offers insight into the contribution of olfaction during different stages of natural behaviour in skilled reaching task.

Removal of the Olfactory Bulbs in Mice Leads to Changes in Affective Behavior

Removal of the olfactory bulbs induces a multitude of behavioral impairments, the most reproducible of which is hyperlocomotion. Olfactory bulbectomy is widely used to model anxiety and depression-like states. In the present study, C57Bl/6 mice subjected to olfactory bulbectomy were tested in standard tests to assess anxiety and depression-like behavior. Removal of the olfactory bulbs in mice was found to increase anxiety and emotionality. Attention in the present work was focused on the fact that hyperactivity induced by bulbectomy can seriously distort the results obtained in anxiety tests. The results lead to the conclusion that the contribution of hyperlocomotion must be taken into account in the interpretation of behavioral measures in the elevated plus maze test.

Subchronic Central Administration of Cannabinoid Ligands Modulates Nociception in Bulbectomized Rats.

Endocannabinoid system is involved in neuropsychiatric disorders such as major depression. The bilaterally olfactory bulbectomized rat is widely used as an animal model of depression. The removal of the olfactory bulbs produces behavioural, physiological, and neurochemical alterations resembling clinical depression. There is increasing evidence that highlights the important role of cannabinoid signalling in depression and nociception. To investigate the effect of CB1 receptor agonist HU 210 and CB1 receptor antagonist SR 141716A administered icv subchronically (for 7 days) on nociception of rats with model of depression - bilateral olfactory bulbectomy (OBX). Experimental model of depression - bilateral olfactory bulbectomy (OBX). Bilaterally olfactory bulbectomized rats were used as an experimental model of depression. HU 210 (5 µg) or SR 141716A (3 µg) were infused icv for 7 consecutive days, starting 15 days after the olfactory bulbectomy. Nociception was examined by applying paw pressure test (analgesy-meter) evaluating the rat pain threshold. On day 7, five minutes after the last microinjection, the rats were tested in an analgesy-meter and their mechanically evoked pain responses were measured in arbitrary units (AU). Microinjections of HU 210 (5 µg) significantly decreased the pain threshold in olfactory bulbectomized rats, while SR 141716A (3 µg) exerted antinociceptive effect by increasing the pain threshold. Data point to an involvement of CB1 receptors in depression-like behaviour and nociception in olfactory bulbectomized rats and support the data for the association between depressive disorder and pain pathways.

Effects of Different Doses of Plant Growth Regulators on Some Characteristics of Summer Snowflakes (Leucojum aestivum L.)

The aim of this study was to determine the effect of different doses and combinations of benzylaminopurine (BAP) and Putrescine elicitor on some plant characteristics of summer snowflake (Leucojum aestivum L.). The experiment was conducted for two years between 2017-2019 in the greenhouse of Uşak University, Faculty of Agriculture and Natural Sciences. Bulbs with ~7 cm circumference and ~9 g weight were used as a material of this study, and was constructed with randomized blocks design with 3 replications. The bulbs were treated for 24 hours before planting with 5, 10 and 15 mg/l BAP; 5, 10 and 15 mg/l Putrescine elicitor in different combinations (16 different combinations). Thereafter, all bulbs were planted in crates. In the first year, only plant height, number of leaves per bulb were recorded and at the end of the second year, the plant height, number of leaves per bulb, number of leaves per daughter bulb, number of bulbs, leaf weight, root length and weight, bulb weight, unit bulb weight, alkaloid contents were measured after removal of bulbs from the soil. According to the results, plant height ranged 19,3-30,0 cm; the number of leaves ranged 6.5 to 12.6, and the number of bulbs ranged 0.9 to 4.6. Root weight was determined between 13.4-47.1 g/parcel, fresh leaf weight ranged 12.4-49.2 g/parcel, and one bulb weight was between 3.5-14.6 g. It was determined that the bulb plant was influenced by different treatments. The maximum growth was noted with 5 mg/l Putrescine elicitor treatment that increased plant height, number of leaves per bulb each year and number of bulbs.

Artificially cooling of onion bulbs stored in brickwork-patterned vertical silos

ABSTRACT Onion is the third most consumed vegetable worldwide, such as potatoes and tomatoes. Its conservation is influenced by temperature and humidity, and greatest losses occur at postharvest due to lack of storage infrastructure. Thus, the aim of this study was to evaluate the effect of partial cooling in vertical silo on postharvest conservation of cured onion bulbs cultivar Bola Precoce. The experimental design was completely randomized, with six replicates, arranged in split plot scheme. Plots consisted of two storage conditions: onion bulbs stored in silo 1 at room temperature (T1) and bulbs stored in silo 2 with artificial cooling (T2). Subplots were two periods of bulb removal from storage (0 and 14 days). We evaluated peel color, using chroma (C*) and internal and external luminosity (L*); relative water content (TRA) of peel and pulp of bulbs and fresh mass loss (PMF) when the experiment was installed and after 14 days for both experiments and at 21 days for T2. The average temperatures obtained in both silos were 30.4 and 16.4°C, respectively. Bulbs of T1 had 14 days shelf life whereas, bulbs of T2 had a shelf life of 21 days. Bulbs of T1 showed lighter peel on day zero. The 14-day storage made the bulbs lighter in T2. In relation to pulp color, storage period made pulp lighter in both treatments. On day 14, bulbs of T1 showed lighter pulp color comparing to bulbs of T2. Both treatments showed similar behavior on day zero for internal chroma. After 14 days storage, internal and external chroma was higher in bulbs of T2. Storage period reduced internal hue only in bulbs of T2 which showed lower internal hue in both evaluation periods. TRA was higher in T1 in both evaluation periods. PMF was higher according to storage period; however loss did not differ between treatments. Storage of onion bulbs in cooled silos increased their viability in 7 days, in relation to storage without refrigeration.

Chronic antidepressant-like effect of EMD386088, a partial 5-HT6 receptor agonist, in olfactory bulbectomy model may be connected with BDNF and/or CREB signalling pathway.

The removal of the olfactory bulbs has been attributed to behavioral changes and neuroplasticity manifesting themselves among others like increases in brain neurotrophin expression and neurogenesis. Earlier data presented that EMD386088, a 5-HT6 receptor partial agonist, exerts antidepressant-like properties after chronic administration in olfactory bulbectomy (OB) model as was it compared with amitriptyline (AMI). The aim of this study was to compare acute and chronic biochemical effects of EMD386088, administered in its antidepressant active (2.5mg/kg) and non-active (1.25mg/kg) doses, found in the open field test in OB rats, with those of AMI (10mg/kg). The levels of 5-HT6 receptor protein and selected neurotrophins in prefrontal cortex (PFC) and hippocampus (Hp) of rats have been examined. 5-HT6 receptor protein and selected neurotrophins: brain-derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB), the product of the immediate early gene c-fos (cFos) protein levels were assessed using a Western blot analysis in PFC and Hp of bulbectomized rats after acute or chronic (14-day) EMD386088 or AMI intraperitoneal (ip) treatment. The acute treatment with EMD386088 caused significant increases in CREB and BDNF protein levels in PFC, and an increase in BDNF in Hp of OB rats, while AMI injection decreased CREB and did not change BDNF levels. After the chronic administration of EMD386088, the increasing levels of BDNF and CREB were still observed in PFC and Hp. The antidepressant-like effect of EMD386088 may be associated with the neuroplasticity activation in PFC and Hp in rats.

The State of Glutathione in Animal Blood Plasma in the Development of Experimental Pathology that Simulates Neurodegeneration of the Alzheimer’s Disease Type

The study of glutathione in the blood plasma of NMR1 mice during the development of a pathology that simulates neurodegeneration caused by removal of the olfactory bulbs (bulbectomy) was carried out in comparison with sham-operated (not subjected to the removal of the olfactory bulbs) and control (before surgery) animals. At 1 month after surgery, a twofold increase in the levels of reduced and oxidized glutathione was detected and an increase in the thiol/disulfide ratio in the blood plasma of bulbectomized mice relative to sham-operated animals was observed. A decrease in the thiol/disulfide ratio as a result of depletion of reduced glutathione and accumulation of oxidized glutathione in animal blood plasma was observed during the period from 3 to 12 months, which is a sign of a pathological process. The major disorders related to oxidative stress were revealed during the maximum manifestation of the disease. During this period, a significant decrease in the reducing capacity of cellular redox pairs, such as reduced glutathione/glutathione disulphide was observed.

Changes in the Brain Endocannabinoid System in Rat Models of Depression

A growing body of evidence implicates the endocannabinoid (eCB) system in the pathophysiology of depression. The aim of this study was to investigate the influence of changes in the eCB system, such as levels of neuromodulators, eCB synthesizing and degrading enzymes, and cannabinoid (CB) receptors, in different brain structures in animal models of depression using behavioral and biochemical analyses. Both models used, i.e., bulbectomized (OBX) and Wistar Kyoto (WKY) rats, were characterized at the behavioral level by increased immobility time. In the OBX rats, anandamide (AEA) levels were decreased in the prefrontal cortex, hippocampus, and striatum and increased in the nucleus accumbens, while 2-arachidonoylglycerol (2-AG) levels were increased in the prefrontal cortex and decreased in the nucleus accumbens with parallel changes in the expression of eCB metabolizing enzymes in several structures. It was also observed that CB1 receptor expression decreased in the hippocampus, dorsal striatum, and nucleus accumbens, and CB2 receptor expression decreased in the prefrontal cortex and hippocampus. In WKY rats, the levels of eCBs were reduced in the prefrontal cortex (2-AG) and dorsal striatum (AEA) and increased in the prefrontal cortex (AEA) with different changes in the expression of eCB metabolizing enzymes, while the CB1 receptor density was increased in several brain regions. These findings suggest that dysregulation in the eCB system is implicated in the pathogenesis of depression, although neurochemical changes were linked to the particular brain structure and the factor inducing depression (surgical removal of the olfactory bulbs vs. genetic modulation).

Electrical Stimulation of the Nucleus Accumbens Shell Reduces Voluntary Ethanol Consumption in Bulbectomized Rats

Background: Alcoholism is often accompanied by depression. It has been shown that deep electrical stimulation of the nucleus accumbens is effective in the treatment of alcoholism. Objective: Despite the promising results of clinical trials, the mechanisms underlying its effects are still unclear. To elucidate these mechanisms, valid animal models are needed. Methods: We investigated the effects of electrical stimulation of the nucleus accumbens shell (NAS) and nucleus accumbens core (NAC) on alcohol intake in bulbectomized rats. Bilateral removal of the olfactory bulbs (OBX) is considered a valid animal model of depression. Results: It was shown that electrical stimulation of the NAS with the described stimulus parameters significantly reduced voluntary ethanol intake in OBX rats. After the cessation of stimulation, this effect became insignificant. In contrast, stimulation of the NAC did not modify voluntary ethanol intake. In sham-bulbectomized animals, voluntary ethanol intake was negligible and ethanol consumption did not alter as a result of electrical stimulation of the NAC or NAS Conclusions: Our study underlines the relevance of the OBX model in the study of depression comorbid alcohol intake. Moreover, it might be useful in the study of the mechanisms underlying the clinical effectiveness of electrical stimulation of the NAS in the treatment of alcoholism.

English

The effect of bulb removal stress on vegetative and flower development of four hybrid lilies at different growth stages and their tolerance to this stress were investigated in this experiment. The tested hybrids were "Royal show" (LA hybrid), "White heaven" (L. longiflorum hybrid), "Sorbonne" and "Premium blond" (Oriental hybrids), four treatments included the bulbs were not removed (control) or removed two, four and eight weeks after planting weeks after planting (WAP) for all cultivars. The results showed that the bulb removal stress had adverse effect on vegetative and flower development of lilies, but the degree of this effect was dependent on the date of bulb removal. It was decreased as the period between planting and bulb removal was increased. Therefore, this stress effect was high when the bulb was removed two weeks after planting (WAP) while it was low when the bulb was removed eight WAP. Thus, the plants at different growth stages have different tolerance levels against this stress and they can survive and successfully complete the life cycle even without their bulbs when these bulbs were removed at late growth stage. The results also showed that the tested cultivars exhibited different response and tolerance to this stress. However, the "Royal show" cultivar was the faster in growth, earlier for flowering and more tolerant with better adapted to bulb removal stress compared to other hybrids.   Key words: Hybrid lilies, vegetative and flower development, bulb removal stress, growth stage.

Chemosensory cues affect amygdaloid neurogenesis and alter behaviors in the socially monogamous prairie vole

The current study examined the effects of pheromonal exposure on adult neurogenesis and revealed the role of the olfactory pathways on adult neurogenesis and behavior in the socially monogamous prairie vole (Microtus ochrogaster). Subjects were injected with a cell proliferation marker [5-bromo-2'-deoxyuridine (BrdU)] and then exposed to their own soiled bedding or bedding soiled by a same- or opposite-sex conspecific. Exposure to opposite-sex bedding increased BrdU labeling in the amygdala (AMY), but not the dentate gyrus (DG), of female, but not male, voles, indicating a sex-, stimulus-, and brain region-specific effect. The removal of the main olfactory bulbs or lesioning of the vomeronasal organ (VNOX) in females reduced BrdU labeling in the AMY and DG, and inhibited the male bedding-induced BrdU labeling in the AMY, revealing the importance of an intact olfactory pathway for amygdaloid neurogenesis. VNOX increased anxiety-like behavior and altered social preference, but it did not affect social recognition memory in female voles. VNOX also reduced the percentage of BrdU-labeled cells that co-expressed the neuronal marker TuJ1 in the AMY, but not the DG. Together, our data indicate the importance of the olfactory pathway in mediating brain plasticity in the limbic system as well as its role in behavior.

Developmental response of hybrid lilies to bulb removal date

The effect of different bulb removal date on the development of underground organs particularly bulblets of four lily hybrids was investigated. Three treatments were used included the bulbs were not removed (control) or removed 6 and 8 weeks after planting .The test hybrids were Royal show (LA hybrids), White heaven (L. longiflorum hybrid), Sorbonne and Premium blond (Oriental hybrids).The results indicated that the development of underground organs of plant was greatly influenced by bulb removal. However, both 6, 8 weeks treatments significantly increased the bulblet production compared to control treatment, but 8 weeks treatment recorded the highest production. The six weeks treatment had stronger induced effect on the emerged shoots from bulblets. The hybrid lilies differed significantly for all observed traits. However, the Royal show cultivar recorded the highest values of bulblets number and weight. The White heaven cultivar showed the best capability of the shoots emergence from the bulblets and from the daughters which grown inside the mother bulbs. Both Sorbonne and Premium blond cultivars had more growth of stem roots, less bulblets, no emerged shoots, compared to other cultivars. All these observations suggest that the technique of bulb removal have a potential use to stimulate the plant to produce more bulblets and the tested hybrids of lilies showed significant differences in their capability for bulblets formation and in their response to bulb removal. Key words: Hybrid lilies, underground organs, bulb removal date, bulblets.

Freezing to the predator odor 2,4,5 dihydro 2,5 trimethylthiazoline (TMT) is disrupted by olfactory bulb removal but not trigeminal deafferentation

2,4,5 dihydro 2,5 trimethylthiazoline (TMT) is a synthesized component of red fox anal secretions that reliably elicits defensive behaviors in rats and mice. TMT differs from other predator odors because it is a single molecule, it can be synthesized in large quantities, and the dose for exposure is highly controllable in an experimental setting. TMT has become a popular tool for studying the brain mechanisms that mediate innate fear behavior to olfactory stimuli. However, this view of TMT as a biologically relevant olfactory stimulus has been challenged by suggestions that the odor elicits fear behavior due to its irritating properties, presumably working through a nociceptive mechanism.To address this criticism our lab measured freezing behavior in rats during exposures to 2 odors (TMT and butyric acid) and H2O (no odor control) following either surgical transection of the trigeminal nerves or ablation of the olfactory bulbs. Our findings (Experiment 1) indicate that freezing behavior to TMT requires an intact olfactory system, as indicated by the loss of freezing following olfactory bulb removal. Experiment 2 revealed that rats with trigeminal nerve transection freeze normally to TMT, suggesting the olfactory system mediates this behavior to TMT. A replication of Experiment 1 that included contextual fear conditioning revealed that the decreased freezing behavior was not due to an inability of olfactory bulb ablated rats to freeze (Experiment 3). Taken together, these findings support TMT's role as an ecologically relevant predator odor useful in experiments of unconditioned fear that is mediated via olfaction and not nociception.

How olfaction disorders can cause depression? The role of habenular degeneration

The removal of bilateral olfactory bulbs (OBs) can result in serious behavioral, neurochemical, neuroendocrine, and neuroimmune alterations in depressed patients. However, there is little information on how olfactory bulbectomy (OBX) leads to depression. Habenular nuclei and their connections are important in the regulation of psychomotor and psychosocial behaviors through afferent impulses of the olfactory system. Therefore, we investigated whether OB lesions lead to habenular degeneration. We used a sample of 50 rats (25 female and 25 male) for this study. Of these rats, five male and five female rats were taken as the control group. The remaining 40 rats (20 male and 20 female rats) constituted the study group, and frontal burr holes were performed at the OB level on these rats. OB cauterization was applied to 10 male and 10 female rats (n=10, 10; study group 1), mechanical OBX was applied to five male and five female rats (n=5, 5; study group 2), and no procedure was performed on the remaining 10 rats (n=5, 5). The psychomotor movements; pregnancy rates; and sexual, feeding, maternal, social, and grooming behaviors for both study groups were observed daily for 3 months. Their OBs, olfactory cortices, and habenular complexes were examined using stereological methods. All of the animals in the study groups, especially in the cauterization group, demonstrated anorexia, nutritional disorders, weight loss, psychomotor retardation, sexual aversion, decreased grooming behavior, and reduced social interaction similar to depression symptoms. As compared to the control group, the pregnancy rates, number of offspring per mother rat, and birth weights in the study groups were lower, whereas the number of stillbirths was higher. Gross anatomical examinations revealed that the OBs of all of the animals in the study groups were atrophied. Histopathological examinations detected prominent neuronal loss due to apoptosis in the habenular structures in the study groups. We detected a relationship between a decreased healthy neuronal density of the habenula and depressive symptomatology in rats with OBX. We suggest that olfaction disorders might cause neuropsychiatric disorders by affecting neuronal degeneration in habenular nuclei.

English

The objective of the present study was to investigate the effect of different bulb removal dates during plant growth on growth and flowering of Asiatic hybrid lily cv. Brunello. The study was carried out in the nursery of Floriculture Unit, Baghdad University, Iraq, from January to April 2012. During plant growth, the bulbs were not removed (control) or removed four, six, eight and ten weeks after planting. The results revealed that buds number, flowers number, flower diameter and plant height were reduced while number of aborted buds increased when the bulbs were removed during active growth. The degree of bulb removal effect was dependent on date of bulb removal. The effect was severe when the bulbs were removed 8 weeks after planting at which time the plants were at the flower bud development; the plants were shorter and more sensitive to buds abortion and produced less flowers with smaller size compared to other treatments. It is necessary to perform further studies to clarify the relation between the bulb and plant development and to investigate the plant physiological and biochemical changes upon bulb removal during plant growth. Key words: Asiatic hybrid lily, growth, flowering, bulb removal.

N-acetylcysteine possesses antidepressant-like activity through reduction of oxidative stress: Behavioral and biochemical analyses in rats

The growing body of evidence implicates the significance of oxidative stress in the pathophysiology of depression. The aim of this paper was to examine N-acetylcysteine (NAC) - a putative precursor of the most important tissue antioxidant glutathione - in an animal model of depression and in ex vivo assays to detect oxidative stress parameters. Imipramine (IMI), a classical and clinically-approved antidepressant drug was also under investigation. Male Wistar rats which underwent either bulbectomy (BULB; removal of the olfactory bulbs) or sham surgery (SHAM; olfactory bulbs were left undestroyed) were treated acutely or repeatedly with NAC (50-100mg/kg, ip) or IMI (10mg/kg, ip). Following 10-daily injections with NAC or IMI or their solvents, or 9-daily injections with a corresponding solvent plus acute NAC or acute IMI forced swimming test on day 10, and locomotor activity were performed; immediately after behavioral tests animals were decapitated. Biochemical tests (the total antioxidant capacity - TAC and the superoxide dismutase activity - SOD) were performed on homogenates in several brain structures. In behavioral studies, chronic (but not acute) administration of NAC resulted in a dose-dependent reduction in the immobility time seen only in BULB rats while chronic IMI produced a significant decrease in this parameter in both SHAM and BULB animals. On the other hand, chronic administration of NAC and IMI resulted in a significant increase in cellular antioxidant mechanisms (SOD activity) that reversed the effects of BULB in the frontal cortex, hippocampus and striatum. Our study further supports the antidepressant-like activity of NAC and links its effect as well as IMI actions with the enhancement of brain SOD activity.

Vagus nerve stimulation ameliorated deficits in one-way active avoidance learning and stimulated hippocampal neurogenesis in bulbectomized rats

BackgroundVagus nerve stimulation (VNS) has been introduced as a therapeutic option for treatment-resistant depression. The neural and chemical mechanisms responsible for the effects of VNS are largely unclear. MethodsBilateral removal of the olfactory bulbs (OBX) is a validated animal model in depression research. We studied the effects of vagus nerve stimulation (VNS) on disturbed one-way active avoidance learning and neurogenesis in the hippocampal dentate gyrus of rats. ResultsAfter a stimulation period of 3 weeks, OBX rats acquired the learning task as controls. In addition, the OBX-related decrease of neuronal differentiated BrdU positive cells in the dentate gyrus was prevented by VNS. ConclusionsThis suggests that chronic VNS and changes in hippocampal neurogenesis induced by VNS may also account for the amelioration of behavioral deficits in OBX rats. To the best of our knowledge, this is the first report on the restorative effects of VNS on behavioral function in an animal model of depression that can be compared with the effects of antidepressants.